System for filling flat-bottom pouches

ABSTRACT

A device for filling stand-alone flat-bottom bags with opposing side edges and a bottom, in particular filling them with liquid including a filling carousel which can rotate about a vertical axis and which has a plurality of holders for one bag each provided on its circumference. The filling carousel has a bag feeding station, a bag opening station, a filling station and a removal station as well as a sealing station. To optimize the filling device and in particular to achieve a higher throughput, a magazine for prefabricated bags and a feeding carousel for the bags is provided in the bag feeding station, containing a plurality of holding devices for one bag each whereby the holding devices can be driven to rotate about a common axis in order to remove each bag individually from the magazine and transfer it continuously to a holder of the filling carousel.

This invention relates to a device for filling stand-alone flat-bottombags of the type described in the definition of the species of claim 1

Such a device is known from European Patent 576 058 B1. The known deviceincludes a filling carousel which revolves continuously and is chargeddirectly by a bag shaping machine. The bag shaping machine processesfilm material from a roll to form a bag strand, then it cuts this bagstrand into individual bags and transfers the individual bags to asynchronizing device which then transfers them to the continuouslyrevolving filling carousel. Although it is mentioned in said publicationthat prefabricated bags from a magazine can also be used, thesynchronizing device must be retained. The type and design of thesynchronizing device is not described, but the description does indicatethat evidently linearly movable arms are used. Nor does it describe howthe bags are held on the filling carousel. The bags are opened by meansof suction cups on the filling carousel and then are filled. Thereafter,the filled bags while still open are transferred to an intermediatewheel from which they subsequently go to a sealing device in the form ofa sealing carousel. Although this publication cites the related art asindicating that efficiency is improved with the known device, the knowndevice still has weaknesses, however. One of these weaknesses is thesynchronizing device which fills the bags on the filling carousel. Thesecond weakness is the intermediate wheel, which transports the openfilled bag, the speed of this transport being limited to ensure that thecontents of the bag, in particular when filled with fluid, do notoverflow out of the bag.

A great variety of such bag filling machines are known in the relatedart. U.S. Pat. No. 3,323,280, for example, discloses a filling carouselfor filling bags with granules. The bags are prefabricated and suppliedin a bag magazine from which they are transferred in a linear movementto the filling carousel. In the filling carousel the bags are gripped bya clamping gripper on each of two opposing side seams; the clampinggrippers can be moved in relation to one another to open the bag. Thismovement of the clamping grippers is relatively complicated to perform.Before closing the opening, which is done by sewing in this case, thebags are rotated, which in turn must be accomplished by a complexsuperimposed movement of the clamping grippers.

U.S. Pat. No. 4,580,473 describes a bag filling device which uses acontinuous conveyor that conveys the bags, which are clamped onto acontinuous conveyor belt, through the different stations. In conveyance,the bag is clamped to only one of these side seams with the help of aclamping gripper. However, the clamped side seam is the forward sideseam, which in turn has the disadvantage that both side walls of the bagare no longer available for opening and on the other hand the throughputof bags is greatly reduced because now the bags have their largestdimensions pointing in the direction of conveyance.

Thus the object of this invention is to improve upon a device of thetype mentioned above which will increase its efficiency.

This object is achieved through the features characterized in claim 1.

With the design according to this invention, a considerable optimizationof the filling device is achieved because the bags can be charged to thefilling carousel continuously and nevertheless they are charged from amagazine of prefabricated bags. Neither the fabrication of the bags northeir being made available in cycles by means of the required severingcut thus forms a limit for the operating speed of the filling carousel.

Advantageous refinements of this invention are characterized insubclaims 2 through 8.

In addition, the embodiment according to claim 9 is also of particularadvantage; when taken alone, i.e., without the charging carousel, thisleads to a significant increase in operating speed of the bags becausenow the charging of the bags can take place in a very simple mannerbecause no second gripping device stands in the way and, in particularin combination with claim 10, the throughput, i.e., the number of bagsthat can be accommodated on the filling carousel is optimized.

In addition, due to the fact that the bags are clamped on only one side,according to claim 11 it is also possible to integrate the suctiongripper for opening the bag according to claim 1 into the holder for thebag. The additional supporting area made available according to claim12, its mobility according to claims 13 and 14 and the possibility ofcentering according to claim 15 permit further optimization of theholding of the bags on the filling carousel and in particular a betteradaptation to subsequent processing steps.

This object is also achieved, optionally only by this feature, by thesealing carousel according to claim 16 because is it capable oftransferring the bags directly from the filling carousel, i.e., withoutan intermediate wheel.

With the design according to claim 17, the sealing device of the [bag]sealing carousel can at the same time assume conveyance functions.

Advantageous embodiments of this invention are illustrated in greaterdetail below on the basis of the drawings, which show:

FIG. 1 a schematic diagram of an inventive device as seen from above;

FIG. 2 the device according to FIG. 1 in a perspective side view;

FIG. 3 a first design principle in a first mechanism of operation of thebag charging station, as seen from above;

FIG. 4 the design principle of the bag charging station according toFIG. 3 in a second mode of operation;

FIG. 5 another design principle of the bag charging station, as seenfrom above;

FIG. 6 a mount of the filling carousel when gripping the bag, as seenfrom above;

FIG. 7 a mount of the filling carousel in opening the bag, as seen fromabove;

FIG. 8 a side view of the mount of the filling carousel, as seen in thedirection of movement;

FIG. 9 a side view of a mount of the filling carousel as seen in theradial direction;

FIG. 10 a perspective diagram of a detail of a filling carousel;

FIG. 11 a perspective diagram of another detail of the filling carousel;

FIG. 12 a perspective diagram of a detail of the sealing carousel;

FIG. 13 a perspective diagram of the sealing jaws of the sealingcarousel; and

FIG. 14 a schematic diagram of a modified device according to FIG. 1, asseen from above.

FIGS. 1 and 2 show schematic diagrams of a device 1 for fillingstand-alone flat-bottom bags 2. Stand-alone flat-bottom bags are widelyused for packaging, and are used among other things for packagingindividual portions of liquids, in particular beverages. Eachstand-alone flat-bottom bag 2 (see also FIGS. 6 through 9) consists oftwo side walls 3, 4 made of a flexible film material joined together ontheir long sides by welds 2 a, 2 b and on their short sides by aninserted or folded stand-alone bottom 5. The side opposite thestand-alone bottom 5 has a filling opening 6 which is also sealed afterthe container has been filled.

The bags 2 are prefabricated, i.e., they are provided with side seams 2a, 2 b and stand-alone bottoms 5 but with the filling opening 6 stillopen and a stock of bags is kept in a magazine 7. The bags 2 are removedindividually from the magazine 7 at a bag feeding station by means of afeeding carousel 8 which is driven to rotate about a vertical axis 8′and they are transferred continuously to a filling carousel 9 which isalso driven to rotate about a vertical axis 9′ which preferably runsparallel to the axis 8′, so that their rotation is in synchronizationwith the feeding carousel 8 and in the direction of the arrow I. On thecircumference of the filling carousel 9, a plurality of holders 10 areprovided at uniform intervals, shown here only schematically and withthe first and last holder for each process step. The filling carousel 9carries the bags 2 that are held in the holders 10 through an openingstation B, where the filling opening 6 is opened by spreading the walls3, 4 of the bag 2. The opened bag 2 then goes into a filling station C,where it is filled with the product, preferably a beverage. This isfollowed by a station D where the bag is rotated 90° about its verticalaxis in preparation for removing the bag from the filling carousel 9 andsealing its upper opening 6 in the sealing station E. The sealingstation E has a sealing carousel 11, which is driven to rotate about anaxis 11′ running parallel to the axes 8′ and 9′, so that rotation is inthe direction of the arrow II and in synchronization with that of thefilling carousel 9, and the filled and sealed bags are transferred to afurther conveyor 12, which is indicated only schematically here.

The individual stations are described in detail below.

FIG. 3 shows a schematic diagram of a first exemplary embodiment of afeeding station A. The feeding station A contains the magazine 7 inwhich the bags are stacked upright and individually one after the other.The magazine 7 extends essentially tangentially to the filling carousel9 and is arranged with its feed opening 7 a tangentially to the feedingcarousel 8. The feeding carousel 8 which can be driven continuously isprovided with a plurality of holding devices on its circumference,designed as suction cups 13 in the exemplary embodiment shown here. Thesuction cups 13 are linked to the rotation of the feeding carousel 8 bya suitable gear 14 (planetary gears having gear wheels are shown here)in such a way that the bags are transferred radially without delay tothe filling carousel 9, whereby in the arrangement of the magazine 7,the feeding carousel 8 and the filling carousel 9 shown here, theorientation of the suction cups 13 remains constant at least duringtheir movement from the feed opening 7 a to the holders 10 of thefilling carousel 9. In the exemplary embodiment shown here, the suctioncups 13 are oriented essentially perpendicular to the front bag 2 in thedischarge opening 7 a and they maintain this orientation. In theexemplary embodiment depicted here, the feeding carousel 8 rotates inthe clockwise direction III while the feeding carousel 9 rotatescounterclockwise in the direction of rotation I shown in FIG. 1. Thesuction cups 13 are controlled so that they apply suction to the frontbag 2 in each case as they pass by the discharge opening 7 a of themagazine 7, conveying that bag in the same orientation into the area ofthe holders 10 of the filling carousel 9, where they transfer the bag toone holder 10 each.

As FIG. 4 shows, the feeding carousel 8 in FIG. 3 may also be operatedin the opposite direction of rotation IIIa, i.e., counterclockwise, whenthe filling carousel 9 rotates in the opposite direction of rotation Ia,i.e., clockwise. The mechanism of action is identical, except that inoperation according to FIG. 4, the bag must be transported over asmaller angular range of the feeding carousel 8.

FIG. 5 shows a modified embodiment of a feeding carousel 8. In thisembodiment, the feeding carousel 8 has a carousel body 15 on which arearranged pivotable arms 16, which also carry holding devices in the formof suction cups 13. The arms 16 are controlled so that they arepivotable from an approximately radial position with respect to the axisof rotation 8′ into an essentially tangential orientation thereto. Themagazine 7 is also arranged tangentially to the filling carousel 9 inthis exemplary embodiment, but its discharge opening 7 a runsessentially radially to the feeding carousel 8. The arms 16 arecontrolled in such a way that they are pivoted out of the dischargeopening 7 a of the magazine 7 into their radial position to accommodatethe front bag 2 in each case, then they retain this position inclockwise transport of the bags 2 picked up in the direction of rotationIII until the transfer of the bags 2 to the holders 10 radially to thefilling carousel which is rotating in the counterclockwise direction Iand in doing so rotate the bag 2 by 180°. The arms 16 are then intangential contact with the carousel body 15 so that the distancebetween the magazine 7 and the feeding carousel 8 need not be too great.

In another arrangement with regard to the position and orientation ofthe magazine, however, another movement pattern of the suction cups maybe necessary and may be implemented.

On the basis of FIGS. 6 through 11, the holding and handling of the bagsin the area of the filling carousel 9 are described.

FIG. 6 shows a top view of the holder 10 at the moment of transfer ofbag 2 from the feeding carousel 8. The holder 10 contains a clampinggripper 17 which consists of two clamping jaws 17 a and 17 b which aremovable in relation to one another by means of a suitable control unit18 (shown here as a knee joint) between an open position in which thebag 2 is released and a clamped position. In the clamped position, theclamping jaws 17 a, 17 b grip the inner side edge 2 b of the bag 2,which is at the left in the figure and is on the inside radially withrespect to the axis of rotation 9′ of the filling carousel 9 and theyhold the bag 2 in an essentially radial orientation with respect to thefilling carousel 9 with the filling opening 6 pointing upward.

The holder 10 also has a support surface 19 which is provided on the topside of a ram 20. The ram 20 can be moved up and down in the directionof the double arrow IV and can be pivoted about its vertical midline 20′in the direction of the double arrow V. The midline 20′ runs in itsextension through the middle of the bag 2. A centering device 21 isprovided on the support surface 19; in the exemplary embodiment shownhere, it includes four holding fingers which stand upward and aredistributed around the circumference of the bag and are spaced adistance apart, where this distance corresponds to the circumference ofthe bag in the area of the bottom 5 when the bag is filled, so that thebag 2 when filled is held securely in the centering device 21. Theholding fingers 21 a extend in height over approximately one-third ofthe height of the bag.

The holder 10 also has an opening device 22 for opening the fillingopening 6 which in the exemplary embodiment shown here contains twosuction cups 27 which are supplied with a vacuum and are moved by meansof holding arms 28, which are only shown schematically. The suction cups27 are arranged on both sides of the bag 2 and pull the two side walls3, 4 apart in a known way for opening the filling opening 6.

As shown best in FIGS. 2 and 10, the bags 2 are transferred to theclamping grips 17 at the feeding station A while the supporting surface19 is still in the lowered state. The supporting surface 19 then travelsupward and is in contact with the standing bottom 5 of the bag. Theopening device 22 is operated and opens the bag. Then the bag is filledthrough filling connections 29 in a known way, while the bag 2 is movedthrough the filling station C together with the filling connection 29assigned to it.

Once the filling is concluded, the clamping grip of the clamping gripper17 is released, as indicated in FIG. 11, and the holding force of theopening device 22 is also released, and the ram 20 together with thesupporting surfaces 19 travels downward. Depending on the design of thesealing carousel 11, the rams 20 may rotate until the side seams 2 a, 2b of the bag 2 are oriented tangentially with the filling carousel 9and/or tangentially with the sealing carousel 11. In this position thefilling opening may be sealed.

Sealing of the filling opening 6 is explained in greater detail belowwith reference to FIGS. 12 and 13. The sealing carousel 11 contains aplurality of sealing grippers 30 which are arranged side by side in thecircumferential direction and are preferably designed as part of anultrasonic sealing device. Each sealing gripper 30 includes a movableclamping jaw 31 with a sealing surface 31 a and the stationary jaw 32with a sealing surface 32 a. The sealing surfaces 31 a and 32 a can bepressed together by the pivoting of the pivotable jaws 31 for clampingthe upper area of the bag 2 about the filling opening 6 and can be actedupon ultrasonically so that the two side walls 3, 4 are joined togetherwith a seal in the area of the opening 6 and the bag 2 is thus closed.The clamping surfaces 31 a, 32 a run tangentially to the sealingcarousel and/or to the filling carousel 9, i.e., in parallel with theorientation of the bag at the sealing station E, so that the sealinggrippers 30 can grip the bag well. By lowering the rams 20 with thefilled bags 2 resting on them in this station, the sealing grippers 30can be moved over the bags without colliding with the fillingconnections, while the bags are still being held by the supportingsurface 19 in sealing so that stretching of the heated material of thebag during the sealing operation under the weight of the full bag isprevented. After sealing the ram 20 continues to move downward so thatthe bag hanging on the sealing gripper 30 is entrained by the movementof the sealing carousel 11, is completely cooled and is transported tothe further conveyor 12 where the grippers 30 are opened so that thebags standing on their standing bottoms can be transported away throughthe linear conveyor 12 or through any other suitable conveyor.

In a modification of the exemplary embodiments described and drawn here,the filling carousel may also be designed with other traditional holdersfor the bags. The welding station need not necessarily be designed as acarousel and set up separately from the filling carousel but instead itmay also be integrated into the filling carousel, for example.

According to FIG. 14, a stationary welding station E′ may be arranged inthe outlet area of the filling carousel 9 in such a way that its sealingmolds 40, 41 are oriented tangentially with the partial circle of thefilling carousel and with the peripheral cap of the upper area of thebags 2, whereby the edges which are initially still open at the fillingopening 6 of a bag pass through the gap pointing tangentially in theperipheral direction between the stationary sealing molds 40,41 andmeanwhile are connected with a liquid-tight seal continuously along theperipheral direction due to the influence of the ultrasonic treatment.The stationary ultrasonic vibrating unit of the welding station E′includes a sonotrode and a mating mold 41 which is designed as an anvilor a rotating roller, for example, and serves as sealing molds in theirinteraction. This arrangement is inexpensive on the one hand while onthe other hand permitting very high material conveyance speeds which inturn permit continuous operation.

1. Device for filling stand-alone flat-bottom bags with opposing sideseams and a bottom, in particular with a liquid, comprising a fillingcarousel that is capable of rotating about a vertical axis, a parallelof holders each for one bag being provided on the circumference of thecarousel, with a bag feeding station, a bag opening station, a fillingstation and a removal station as well as a sealing station beingassigned to the filling carousel, the bag feeding station (A) having amagazine (7) for prefabricated bags (2) and has a feeding carousel (8)which contains a plurality of holding devices (13) each for one bag,whereby the holding devices (13) can be driven to rotate about a commonaxis (8′) so that each bag (2) can be removed individually from themagazine (7) and the bags (2) can be transferred continuously to one ofthe holders (10) of the filling carousel (9).
 2. Device according toclaim 1, wherein the holding device (13) of the feeding carousel (8)includes a suction gripper.
 3. Device according to claim 1 wherein theholding device (13) of the feeding carousel (8) can be moved in relationto the rotation of the feeding carousel (8).
 4. Device according toclaim 3, wherein the holding device (13) is arranged so it can rotateabout an axis on the feeding carousel (8).
 5. Device according to claim3 wherein the orientation of the bags (2) in the magazine (7)corresponds essentially to the orientation of the bags (2) in thefilling carousel (9), whereby the holding device (13) of the feedingcarousel (8) is movably controlled so that the orientation of the bagsbetween the magazine (7) and the filling carousel (9) remainsessentially unchanged.
 6. Device according to claim wherein theorientation of the bags (2) in the magazine (7) corresponds essentiallyto the orientation of the bags (2) in the filling carousel (9), wherebythe holding device (13) of the feeding carousel (8) is movablycontrolled so that the bags (2) can be rotated by 180° between themagazine (7) and the filling carousel (9).
 7. Device according to claim6, wherein the holding device (13) is situated on a pivot arm (16) whichcan be pivoted from an approximately tangential orientation to thefeeding carousel (8) into an approximately radial orientation thereto.8. Device according to claim 1, wherein the opening station (B) hassuction grips (27) which grip on opposite side walls (3, 4) of the bag(2).
 9. Device according to claim 1, wherein the holder (10) of thefilling carousel (9) includes a clamping grip (17) for gripping andholding the bag (2) on just one side seam (2 a) of the bag (2). 10.Device according to claim 9, wherein the bag (2) is oriented with itsside seams (2 a, 2 b) radially to the axis of rotation (9′) in thefilling carousel (9), and the clamping grip (17) grips the side seams (2b) that is on the inside radially.
 11. Device according to claim 1,wherein the holder (10) has a clamping grip (17) for gripping a sideseam (2 b) of the bag and has two suction grips (27) which are arrangedsymmetrically with the clamping grip (17) and can be moved in relationto one another, each gripping a side wall (3, 4) of the bag (2) foropening the bag (2).
 12. Device according to claim 1, wherein the holder(10) includes a support surface (19) for the stand-alone bottom (5) ofthe bag (2).
 13. Device according to claim 12, wherein the supportingsurface (19) can be moved up and down.
 14. Device according to claim 12,wherein the support surface (19) can be rotated about a vertical axis(20′).
 15. Device according to claim 12, wherein the support surface(19) includes a centering device (21) for the bags (2).
 16. Device,according to claim 1, wherein the removal and sealing station (E)includes a sealing carousel (11) having a plurality of sealing devices(30) revolving around a common axis (11′) for one bag (2) each which isarranged directly adjacent to the filling carousel (9) whereby thesealing device (30) is movable to remove a bag (2) via the holder (10)of the filling carousel (9).
 17. Device according to claim 16, whereinthe sealing device (30) has sealing jaws (31, 32) with a holdingfunction for sealing bag (2) and for removing the bag (2) from thefilling carousel (9) and for transferring the bag (2) to a furtherconveyor (12).
 18. Device according to claim 1, and a stationary weldingstation (E′) is provided on the filling carousel (9) which can be drivento revolve continuously, the welding station having sealing tools (40,41), the sealing tools (40, 41) having a gap oriented tangentially tothe peripheral web of the bag (2), passing through the open edges of thetangentially oriented bags continuously, and being connected to oneanother along the peripheral edge thereby.
 19. Device according to claim18, wherein the welding station (E′) has at least one stationaryultrasonic welding device, in particular with a sonotrode (40) and amating tool (41).